I'm getting sound but no picture at first then after 5 minutes or so the picture will come on.

Contact the authorized service centre for Sony. This is not a fault that a normal user can do anything. Electro help

Could be the ballast boards for the white light.

Ur LCD inverter board is dead.This board help the LCD screen to have a backlight to give u picture.Replaced the LCD inverter board will get ur picture back.Tries these websites Shopjimmy.com,Ebay.com to buy a refurbish LCD inverter board for the replacement.It a long board in shape,it pretty easy to replaced.

Ur LCD inverter board it dead,replaced it will get picture back.

There is possibly a loose solder joint in the horizontal drive circuit. There is a little coupling coil just before the horizontal output that will get loose. This should not be real expensive to have repaired.

souns like an over heating isue
try cleaning out the unit
take it to the local mechanic have him give your tv a ******* (with compressed air )
heck hes been screwing you so his kids can go to coledge for years whynot get a freebe?

Is it ok when you watch regular TV thru the cable or sat?

So, where are the answers?

The tv is shutting down because of a power problem. It could be the power transformer or a color gun overheating. Expect at least a couple of hundred dollars to fix it. Some shops will do house calls for around $65 and can diagnose the problem and give you an estimate. Usually they can just remove the board, take it to the shop and repair it, then reinstall it.

It may be overheating, check fans and or obstructions of the vents